Hypercalcaemia in a dog with primary hypothyroidism.

Area of Science:

• Veterinary Medicine
• Canine Endocrinology
• Comparative Pathology

Background:

• Primary hypothyroidism is a common endocrine disorder in dogs.
• Hypercalcaemia, or high blood calcium, can be caused by various conditions, including certain cancers and parathyroid gland issues.
• Investigating the underlying cause of hypercalcaemia is crucial for appropriate treatment.

Observation:

• A 7-year-old female beagle presented with clinical signs consistent with hypothyroidism and concurrent symptomatic hypercalcaemia.
• Diagnostic workup, including imaging and cytology, ruled out common causes of hypercalcaemia.
• Low plasma parathyroid hormone levels were noted, suggesting a non-parathyroid source for the hypercalcaemia.

Findings:

• Treatment with thyroxine, a hormone replacement therapy for hypothyroidism, led to the resolution of hypercalcaemia.
• The resolution of hypercalcaemia occurred approximately 9 weeks after initiating thyroxine therapy.
• This case represents the first documented instance of primary adult-onset hypothyroidism associated with symptomatic hypercalcaemia in a canine patient.

Implications:

• This finding suggests a potential link between primary hypothyroidism and hypercalcaemia in dogs.
• Further research is warranted to elucidate the mechanisms behind this association.
• Clinicians should consider evaluating calcium levels in hypothyroid dogs and vice versa.